Allergic diseases, such as bronchial asthma or allergic rhinitis, are induced as follows: firstly, antigen-specific IgE production is induced, and then, from mast cells, basophils and the like, activated by the induced IgE, various chemical mediators such as histamine, eosinophil chemotactic factor in allergy (ECF-A), leukotrienes, platelet-activating factor (PAF) and thromboxane are produced and released. Specifically in tissues, the mast cells release these chemical mediators, and therefore play an important role in development of allergic diseases.
Human mast cells are differentiated into tryptase positive cell (MC-T) and both tryptase and chymase positive cells (MC-TC), according to the granule content of proteolytic enzyme in the mast cells. MC-T are mainly distributed in the lung tissues and the gastrointestinal tract mucosa, whereas MC-TC are distributed in the skin tissues. These mast cells, unlike cells of other leukocytes, leave bone marrow for the peripheral environment as pluripotent stem cells, and differentiate into MC-T or MC-TC, followed by adhesion to either lung or skin fibroblasts. Since it is believed that such mast cells play a major role in development of allergic diseases, it is necessary to specifically detect and separate the mast cells in order to clarify the physiological functions of the mast cells.
However, heretofore, no cell surface antigen specific to the mast cells has been known. Since the antibody against the cell surface antigen specific to the mast cells will allow us to specifically remove or eliminate the mast cells, identification of the cell surface antigen specific to the mast cells has an important meaning not only in clarification of the underlying cause of allergic diseases but in treatment thereof.
An object of the present invention, which was made to solve the above problem, is to provide a mast cell surface antigen, DNA thereof, and an antibody against the antigen.